Classifier.



P. ARGALL.

GLASSIFIBR.

"APPLIOATION FILED JULY 20, 1909.

Patented Nov. 19, 1912.

3 SHEETS-SHEET 1.`

P. ARGALL.

GLASSIPIBR.

APPLIGATIONFILED JULY zo, 1909.

l 944,84.) l Patented Nov. 19, 1912.

3 SHEETS-SHEET 2.

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P. ARGALL.

GLASSI'FIER.

PPLIOATION FILED JULY zo, 1909.

1944118440 Patented Nov. 19, 1912.

3 SHEETS-SHEET 3.

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PHIVILIP ARGALL, F DENVER, COLORADO.

CLASSIFIER.

Specification of Letters Patent.

Patented Nov. 19, 1912.

Application filed July 20, 1909. i Serial No. 508,626.

. primary objects a novel and etlicient method of separating slime from sand, and a novel and efficientapparatus facilitating the carrying of said method into practical effect.

The present invention may be said to be ancillary to an all sliming process wherein all the ore is reduced Ato slime and in the course of which processit is important that the slimes be separated from the sands as discharged from the grinding mills and the latter returned to the mills to be ground to slime; in this way the slime is separated from the sands as fast as formed and the sand returned to the mills until completely ground into slime of the desired fineness. It is well known that the clean separat-ion of slime from sand is an essential feature in ore dressing, and more particularly in carrying forward the ordinary cyanid process where a clean separationof the sands is a condition precedent to good leaching in the extraction vats, while the slime is best treated by agitation.

Looking to the efective'separation of the sands from the slimes, various edorts have heretofore been made, for instance, by the use of hydraulic classifiers but the results have at best been only partially successful, whereas by the use of a method and apparatus in keeping with my invention herein, it has been demonstrated that as a rule, substantially slime-free sand and sand-free slime are secured.

Although my method of and apparatus -for classifying or separat-ing the sands and slime are, as will appear to those skilled in the art, capable ofv use alone as necessity or occasionY therefor may arise, the same is peculiarly adapted for use, as above stated, ancillary to or as a partof a continuous ore treating or extraction process.` A process in keeping with this latteridea comprises the initial crushing of the ore in a stamp mill or equivalent in the presence of a cyanid solutlon from which the pulp is delivered to a distri-buter, the distributer in turnfeeding tomy improved classifying apparatus 1n connection with which the novel methodI of bodily moving the sand with the entangled slime, preferably while agitating the same, utilizes the force of the impelling medium in opposition to the inertia of the body of sand and slime to express the solution and slime from the sand, thus unwatering said sand. After the performance of this feature of the process, the separat-ed slimes and sands are conducted from my classifier, the latter into a leaching tank wherein a cyanid solution reduces the gold and silver contents to a minimum, and the latter (the slimeY is floated over a novel Weir which I have devised for that purpose, to a settling tank where the slime is thickened. From the settling tank the partially cleared solution is returned to the storage tank which supplies the stamp batteries,

`while the thickened slimes are delivered to an agitator and agitated in the presence of a stronger solution of cyanid until the maximum extraction of the precious metals lis obtained, when the combined slime and solution is conducted to a suitable filtering apparatus, preferably of the type disclosed in my Patent No. 822,812, dated June 5, 1906, in which the gold or precious metal bearing solution is finally separated from the slime, t-he latter being washed and delivered to the waste dump. I also, when expedient or desirable, wash and filter the sand prior to its discharge from my classifier into the leaching tank, the slimes and water from this filtering step being also conveniently conducted back to the storage tank.

There are many features both in matter of detail and arrangement of parts inherent in an apparatus constituting an embodiment of my present invention, all of which will .probably be apparent from the detailed description hereinafter contained, when read in connection with the accompanying drawings forming part hereof and wherein such an embodiment is illustrated. It may be here noted, howeverthat the classifier comprises what may be said to be three operating portions, first a settling portion, second an' unwatering portion, and third a filtering portion.

Novel features reside in the utilization of a trough preferably inclined and oppo,

sitely disposed upwardly and inwardlyv roilo ta-tin "spiral conveyers therein; a weir over Whit, the water will flow with the slime,

I shallow trough may be used, the oppositely disposed conveyers being separated to per- .lnit the sand to bank up therebetween and the slimes to flow outwardly over the edges of said shallow trough; a filter comprising separated bars relatively arranged and formed to support a sand filtering bed over which the sand being treated may be fed,

and a discharge for the slime and solution therebeneath; additional longitudinally disposed filtering means projecting into the space bet-Ween the spiral conveyers and adjoining the inner ends of the opposite filter beds such as last referred to; and an arrangement whereby the unwatering portion of the apparatus will permit the expressed solution and slimes to feed back into the settling portion of the apparatus from which the slimes may be floated over ata predetermined level and out of said settling portion.

In the drawings: Figure l is a diagrammatic lillustration of an apparatus in connection with which a continuous process4 as defined hereinabove may be carried into practical effect, and inasmuch as the diagram is seemingly sufficiently clear to be` readily understood when assisted by the description heretofore given. such diagram will not be further hereinafter specifically alluded to; Fig. 2 is a plan view of my improved classifier; Fig. 3 is a longitudinal vertical sectional view taken on a line between the spiral conveyers of Fig. 1; Fig. et is a transverse sectional view on the line .r-m of Fig. 3, Fig. 5 is a similar view on the line y-/y of Fig. 3, and Fig. 6 is a like view taken on the line s-a of the same figure.

In the drawings wherein like reference characters designate the sameparts in the several views, A represents an elongated distributer or feed launder disposed transversely of the apparatus to receive the pulp (crushed ore and cyanid solution) from the stamp batteries. The distributer has in its forward wall a a series of openings a arranged in the bottom of said Wall from which the pulp is discharged into the forward end of the settling portion B of the classifier, said classifier being represented in its entirety in Fig. 3.

C is the unwatering portion of the classifier and D the filtering portion thereof. The portions B, C and D have a common I .bottom E and side walls F constituting .a

continuous trough, said trough being arranged at an inclination varying as the case may be from ten degrees to twenty-five degrees from the horizontal, probably'fifteen degrees for ordinary silicious ores. The inner or rear end of the trough being that end of the device which constitutes the settling portion, has the side walls extended upwardly a substantial extent `with the top Y edges b Vthereof terminating in a horizontal plane to give a substantial depth to the trough at this point and to enable the main tenance of a water level, represented in dotted lines at b', within the portion B of the apparatus and partially through the portion C thereof. A weir G consisting of a strip set truly level over which the watery solution carrylng the'slime in suspension passes in a thin stream, projects forwardly from the closed inner end of the trough and terminates in the plane of the desired water level, affording an overflow space g behind the. weir, having a discharge g through the end wall preferably in communication with the settling tank. The upper portions of the side walls of the settling portion B are flared upwardly and outwardly at about sixty degrees to provide a settling area sufficient for the feed volume passing through the machine. Mounted in suitable bearings z" solid or ribbon form s iral conveyers (the latter being preferable ihr sticky ores) are arranged side by side` a suitable distance apart and rotated conveniently at about three to eight, preferably five, revolutions per minute, through the instrumentality of suitable gearing I in opposite directions inwardly and upwardly, clearly represented by the arrows. Fig. 2. These conveyers are preferably 16 inches in diameter and Q4 feet in length. They are mounted a convenient distance above the bottom E of the trough to provide a clearance of approximately four inches to enable a portion of the sand to be carried upwardly by the conveyers from the settling portion F to forma bed or bottom. in the unwatering portion E of the conduit conforming to the conveyers and over which the main body may feed in its course onward and upward.l The lower portions of these screws not only convey the sand upwardly as it settles in the settling portion of the apparatus, but help materially in connection with the water to keep the slime in suspension until fioated of'Il over the weir. On the bottom E of the unwatering portion C, I secure a air of angle irons K located just outside of) the edges of the conveyers and of but relatively short-.height to constitute a shallow trough c and outer overflow receiving channels K.-

The bottom or filter bed of the filtering portion D of the apparatus. is formed as follows: On the bottom of this portion of the device are secured longitudinally disposed angle-irons Z, m, suitably spaced to support. at opposite sides of the trough and beneath the conveyers a series of angular slats or bars L arranged transversely of the trough and closely together. These bars are supported by the angle irons so as to leave channels M therel'ieneath opening to a. receiver O at the lower or inner end of the filtering portion I) and which latter is adapted to communicate through a pipe o with the storage tank which supplies the batteries as hereinbefore recited. The slats or bars are conveniently triangular in cross section, their flat bases resting upon the supporting angle irons and their apices pointing upwardly to provide grooves between adjoining bars for the reception of sharp sand represented at, P and' through which the solution is filtered to the channels M and thence to the receiver O. ,Air other element of the filtering is constituted by a hollow inverted V-shaped member Q, supported upon the angle irons m to provide a channel N therebeneath and between said angle irons. this member Q being formed either of metal or wood, perforated as at and covered with canvas or other filtering substance as indicated at Q2.

F rom the foregoing description the operation of my improved classifier and the process, the carrying out. of which is helped by said apparat-us(` may now be followed: The pulp composed of the crushed ore and cyanid solution from the stamp batteries (say for example a twenty mesh pulp with six parts of water to one of ore) is supplied through the instrumentalitg7 of the distributer or feed launder A to the upper end of the settling portion F, and owing to the agitation of the material under the constant actuation of the spiral conveyers I, at a speed of five revolutions per minute, the greater portion of the slime is separated from the sand and floats over the weir at the water level o and is discharged at g. It is to be here observed that the devising of the proportions-and arrangement of the weir has been a delicate and diiiicult proposition. Generally speaking, it must be such that the velocity of the water passing over it will not also carry with it the fine sand. Specifically, in connection with the nature and parts of the apparatus herein disclosed I have found that a six foot weir gave sandfree slime, all passing one-lumdred and fifty screen aperture from a feed amounting to approximatelyv six tons of ore per hour. As the sand settles to the bottom of the trough in the settling portion F, a sand bed is gradually formed and progressively built upwardly upon the inclined bottom of the trough, the upper surface of which is complementary to the contour of the conveyers. As this bed or bottom is formed the main or movable body of sand with its confined slime is forced upwardly by the spiral con- `veyers from the settling portion Blinto the unwa-tering portion C, the action of the oppositcly inwardly and upwardly rotating conveyers upon the sand body being shown in F ig. '5, wherein it appears that the action of the conveyers is to build up, while constantly changing and displacing the sand particles, therebetween. T he shallow trough )if fills with the sand and the solution and slime extracted from the moving body of sand seeps or iowsoutwardly over the sides K of said trough into the return channels K whence it runs down the inclined trough back into the settling portion F. This extraction of theA solution from the moving body of sand is accomplished by the agitation of the body under the influence of the spiral conveyers, and owing to t-he pressure upon the body created by the force which moves the same forward and upwardly resisted by the inertia of the body itself. From the unwatering portlon C the sand is forced by the conveyer over the filter bed hereinbefore described and the solution and any remaining slime is filtered through the filter bed and discharged into the receiver O, the slime-free sand being discharged through an opening t5 at the upper end of the trough into the leaching tank as before stated.

Owing to the'niaintenance of the water level not only in the settling portion B, but also in the'lower end of' the portion C, the solution acting in conjunction with the conveyers serves effectively in liberating the slime entangled within the sand as it leaves the settling portion B. At times it may be desirable to wash the sand prior to its discharge from the filter end of the apparatus and to accomplish this, water sprinkling pipes T may be disposed, one above each of the spiral conveyers, whereby to discharge water upon the sand being filtered, the water passing through the lter bed down into the receiver O' as is apparent.

lihile Ifhave herein disclosed a special apparatus constituting a practical embodiment of the invention, it is readily understood that the invention may be readily embodied in other forms and arrangements of apparatus without in the least departing from the spirit of the invent-ion.

1. In an ore treating apparatus, a trough, spiral conveyers'therein separated from each other and from the bottom of the trough to leave a space between said bottom and said conveyers, means for rotating the conveyers inwardly and upwardly relative to each other, and members in said trough constituting a relatively shallow trough within said first mentioned trough, in combination with a sett-ling chamber constituting a continuationl of the first mentioned trough, and extensions of the spiral conveyors working in said settling chamber, the latter having a discharge for the slime from said settling chamber.

2. In an ore treating apparatus, a settling portion adapted to contain water, a weir over which the water may be'floated, an unwatering portion adjoining the settling portion having a conducting channel at one side thereof feeding back to the settling portion, and feeding means extending through the settling and unwatering port-ions.

3. In an ore treating apparatus, a settling portion, adapted to contain water,aweir over which the'water may be floated, an unwatering portion adjoining' the settling portion having conducting channels at opposite sides of the unwatering portion feeding back to the settling portion, and conveying means extending through the settlingr and unwatering portions.

4. In an ore treating apparatus, a settling portion adapted to contain water, a Weir over which the water may be floated, an unwatering portion adjoining the settling portion having a conducting channel at one side thereof feeding back to the settling portion,

and parallel coperating screwy conveying means extending through the settling and unwatering portions. A

5. In an ore treating apparatus, a settling portion adapted to contain water, a weir over which the water may be floated, an unwatering portion adjoining the settling portion having conducting channels at the opposite sides of the unwatering portion feeding back tocthe settling portion, and parallel coperat-ing screw conveying means extending through the settling and unwatering portions.

6. In an apparatus of the character described, the combination with. a settling chamber part having a Weir, of an unwatering trough leading from the chamber, a plu-pv rality of spiral conveyers located in the trough and extending from the settling chamber, means for driving the conveyers and a return conduit in the unwatering trough leading to the settlin chamber.

In testimony whereof I a X my signature in presence of two witnesses.

PHILIP ARGALL.

Witnesses JAMES A. MCCLURG, J. PARK GRAYBELL. 

